DE2126682B2 - Process for the production of acrylonitrile from propylene - Google Patents

Description

works and uses a catalyst, the object of the invention is therefore to provide a process

Composition without taking into account the carrier content of the empirical formula with a special catalyst system so that it allows acrylonitrile to be extracted from Pro

pylene, containing oxygen or free oxygen

TloPftMocFedBieX / Off gases and ammonia in high selectivity and with

excellent yield per pass.

corresponds, in which X is Ni, Mg, Co or Mn or a When working with this catalyst, the formation of a mixture of two or more of these elements should be 25 undesirable by-products, in particular, and α should have a value of 0.01 to 1.0, b a carbon monoxide and carbon dioxide, if possible below a value of 0.01 to 3.0, c the value 12, d a value. Furthermore, with this catalyst it should be possible from 0.1 to 5.0, e a value of 0.5 to 3.0, / one, at a relatively low tempe value of 2 to 12 and g a value of 38.9 to work until ratures. This task is done by the 69.0. 30 invention solved.

The invention now relates to a process for the preparation of acrylonitrile by reaction of propylene with ammonia and oxygen or

inert gases containing free oxygen

35 elevated temperature in the gas phase in the presence of calcined, phosphorus, molybdenum, iron and bismuth containing supported oxide catalysts and optionally steam, which is characterized

The production of acrylonitrile by oxy is that at temperatures of 350 to 480 ° C, dation of propylene with oxygen in the presence of 40 pressures of 0.7 to 5 atm and a molar ratio of ammonia and various catalysts propylene to ammonia to oxygen from
is known. For example, from the German
Patent specification 1127 351 bismuth, tin or antimony salts of molybdic acid, phosphomolybdic acid 1.0: 1.0 to 2.0: 1.5 to 3.5
or phosphotungstic acid as catalysts
knows, which can also be applied to carriers.

In the case of which works in German Patent 1,243,175 and uses a catalyst, the process of which is described, the reaction is carried out in a counter-composition without taking into account the type of support of a catalyst, which is made up of a content of the empirical formula
Mixture of oxides of iron, bismuth, molybdenum 50
and phosphorus and which is applied to a carrier. Incidentally, in this patent specification TI “P & Mo _c Fee Bi _e X / O _g
the relevant state of the art dealt with before December 7, 1960. In the Japanese disclosure

Document 14 093/1966 corresponds to a catalyst system from FIG. 55, in which X describes Ni, Mg, Co or Mn or an oxide of copper and antimony. In the mixture of two or more of these elements is USA patents 3 186 955, 3 248 340 and as well as α a value from 0.01 to 1.0, b a value before 3 280 166 are mixtures of bismuth and molybdenum 0.01 to 3.0, c the value 12, d a value from 0.1 to oxide as catalysts and in the German version 5.0, e a value from 0.5 to 3.0, / a value of 2 to 1 205 502 is a catalyst system composed of the 60 12 and g has a value of 38.9 to 69.0.
Oxides of uranium and antimony are described. All Pro. Used in the method of the invention

however, these known methods have disadvantages. pylen does not have to be particularly pure and can ζ. Β One of the disadvantages is the relatively low certain amounts of low molecular weight saturated Selectivity of the formation of acrylonitrile. Contains hydrocarbons such as propane. Ali By-products are, among other things, carbon mono- 65 Source of oxygen can be pure oxygen, air, mi oxide, carbon dioxide, acrolein, acetaldehyde, aceto-oxygen enriched air or any other free air nitrile and hydrogen cyanide are formed, whereby the oxygen-containing gas serve. From economy The amount of acrylonitrile drops. For the formation of these borrowed grounds, air is preferably used. to

Increasing the selectivity of the acrylonitrile formation speed is usually 50 to 2000 hours.

a diluent such as nitrogen, carbon - preferably 100 to 1000 hours - ¹ .

dioxide, argon or, preferably, steam, used

will. For the production of the acrylonitrile catalyst system with high selectivity and excellent

can thallium or thallium compounds, such as 5 neter yield per pass and with only lower

Thallium nitrate, thallium carbonate or thallium chloro- Formation of carbon monoxide and carbon dioxide

rid, molybdenum compounds such as ammonium molybdenum sites. Furthermore, the catalyst has a sufficient one

dat, molybdenum oxide, molybdic acid or phosphorus and satisfactorily long activity, and the thallium in

molybdic acid, phosphorus compounds, \ »ie the phosphorus catalyst system is not used in the conversion

phosphoric acid, ammonium phosphate or phosphorus pentio volatilized.

oxide, iron compounds such as iron (III) nitrate or the following examples illustrate the invention. Iron (III) chloride, bismuth compounds such as bismuth nitrate, bismuth chloride or bismuth oxide, magnesium compounds such as magnesium nitrate or magnesium - Example 1
chloride, cobalt compounds such as cobalt nitrate or ¹⁵
Cobalt chloride, nickel compounds such as nickel nitrate

or nickel chloride, and manganese compounds, -, vie (A) 1.33 g thallium nitrate, 10.10 g iron (Hl) nitrate,

Manganese nitrate or manganese chloride can be used. 7.18 g manganese nitrate, 6.41 g magnesium nitrate, 7.28 g

Cobalt nitrate and 39.99 g of nickel nitrate are suitable as supports for the catalyst system

For example, silica, alumina, aluminum oxide, silicon are dissolved in 300ml of distilled water. 12.13g bismuth

carbide and titanium oxide. The proportion of the carrier depends on the nitrate.

of its kind. Usually less than pitric acid is dissolved. The two solutions are

90 percent by weight, preferably 5 to 90 percent by weight. The resulting mixture becomes a solution

percent, carrier, based on the total catalyst of 52.98 g of ammonium molybdate in 300 ml of 3.5

sator, used. The catalyst is normally given 25 percent strength by weight aqueous ammonia solution,

used in the form of tablets or granules. the 0.23 g of 85 weight percent phosphoric acid

The catalyst can be used according to numerous known holds. The resulting slurry will be prepared by the 100 ml method. For example, a 20 percent by weight silica sol can be mixed with a thallium salt, iron salt, bismuth salt, phosphorus and evaporated to dryness until the development of phosphorus compound and magnesium, cobalt and nitrous gases ceases. Thereafter, the RückNickel- or manganese salt or a mixture of two score 3 hours to a first calcination at 300 ⁰ C or more of the last-mentioned salts is subjected, cooled and ground in a. The aqueous solution of a molybdate such as ammonium powder obtained is pressed into tablets and 6 hours of a molybdate, Enter, subjecting the slurry obtained in the second calcination at 550 ⁰ C. Mix it with a carrier, the mass to dryness 35 holds a catalyst, the active components evaporate and at elevated temperatures at that of the formula
Calcine air. After cooling, the catalyst is ground and made into cookies, pills or

Deformed beads. _{A Tl 012} P ₀₁₀₈ MOi ₂ Fe ₁ Bi ₁ MnJMg ₁ COiNi ₅₁₅ O _{4810 is added} to the catalyst

given such a particle size that it is suitable for the flow 40
or fixed bed is suitable.

The preparation of the acrylonitrile according to the result. The content of carrier is omitted,

inventive method can be in a fluidized bed or (B) In a reaction tube made of glass with an inner

Fixed bed take place. The reaction temperature depends on the diameter of 10 mm, 6 ml of the obtained

the type of catalyst composition. Ordinary filled 45 catalyst and heated to 41O ⁰ C. On that

borrowed one works at temperatures of about 350 to is a gas mixture of propylene, ammonia, acid

48O ⁰ C and pressures of 0.7 atm to fifth Molverhält- The cloth, steam and nitrogen in a molar ratio
nis from propylene to ammonia to oxygen
approximately

50 1.0: 1.2: 2.8: 9.0: 6.8

1.0: 1.0 to 2.0: 1.5 to 3.5.

at a space velocity of 550 hours - ¹

When using steam as a dilution pipe. The propylene conversion is 100%, and the This is usually medium in quantities of high selectivity for the formation of acrylonitrile, carbon 18 mol, preferably in amounts of 1 to monoxide and carbon dioxide is 80%, 7.0% and 10 moles, used per mole of propylene. The space- 6.1%, calculated according to the following equations:

_. , χ / o / \ converted propylene (mol)

Propylene conversion (%) = - - - 100,

propylene used (mol)

S 1 kt "Tt t ^a / \ - weight of carbon atoms in the product _" »

Weight of carbon atoms in the converted product

Examples 2 to 14

According to Example 1, various catalysts are prepared and for the preparation of acrylonitrile used. The results are shown in Table I.

Table I.

at
game * ■ Tl P. Mon Catalyst Composition 1 Ni Mg Co Mn C. 2.
Calci-
low
at 0.2 0.08 12th Fe j Bi 1 4.5 0 o! 4th 48.0 ⁰ C 2 0.2 0.08 12th 1 1 7.5 0 0! 1 48.0 550 3 0.2; 0.08 12th 1 1 0 8.0 0 0.5 48.0 550 4th 0.2 0.08 12th 1 1 0 0 6th 2 47.5 550 5 0.2 0.08 12th 1 1 5.5 2.5 0 0.5 48.0 550 6th 0.2 0.08 12th 1 1 5.5 0 2.5 0.5 48.0 550 7th 0.5 0, G8 12th 1 1 4.5 0 4th 0 47.7 550 8th 0.2 0.08 12th 0.5 1 4.5 4th 0 0 47.7 ^! 525 9 0.2 0.08 12th 0.8 1 8.5 _; 0 0 0 47.7 525 10 0.2 0.08 12th 0.8 1 0 8.5 0 0 48.0 525 11 0.2 0.08 12th 1 1 0 0 8.5 0 48.0 525 12th 0.5 0.3 12th 1 1 4.5 4th 0 0 48.25 550 13th 0.2 0.08 12th 0.5 4.5 4th 0 0 49.7 525 14th 0.8 550

Reaction
conditions ; Space- Propy
len (Continuation of table O, N, D. Propylene
turnover ^: acrylic Selectivity, CO, React ge 1 2.9 6.3 ever acid
nitrile % 2.2 at functional Schwin- 1 3.0 6.6 By- ; 88 5.0 game tempe- digkeii
hours 1 2.9 6.9 corridor, : 82 4.5 rature,
"C 540 1 Charge, mole 3.0 6.8 % 79 CO 5.5 440 550 1 3.0 6.6 steam 96 84 2.0 2.9 2 410 405 1 2.8 6.4 8.7 96 87 3.2 5.5 3 430 540 1 ; NH ₅ 3.0 7.6 8.6 90 82 4.8 3.8 4th 390 540 1 1.1 3.1 7.4 4.8 99.6 85.5 5.6 6.1 5 390 410 1 1.1 2.9 6.8 8.9 96 83.4 1.8 6.2 6th 410 476 1 1.2 2.9 6.8 8.8 100 80 3.8 4.3 7th 430 580 1 1.2 3.0 7.5 8.7 91 78 2.5 3.8 8th 410 620 1 1.2 3.0 6.5 4.9 99.7 84 2.1 4.0 9 430 394 1 1.1 3.0 6.6 4.8 100 86 5.0 10.3 10 430 518 1.2 3.8 90 79 4.6 11 440 560 1.2 3.8 90.5 3.0 12th 410 372 1.1 4.8 90 1.7 13th 390 1.1 7.5 99.6 5.7 14th 1.1 0 1.7 1.6

Comparative examples 1 and 2

Catalysts are prepared according to Examples 1 and 10, but without using thallium nitrate and used to make acrylonitrile. The results are shown in Table II.

Table Π

Comparative example

Catalyst composition

2. Calcination at ⁰ ° C

Reaction conditions

Reaction temperature ^{, 0 C}

Space velocity hour - ¹

Po ₁ O ₈ Mo ₁₂ Fe ₁ Bi ₁ Ni ₅₁₅ Mg ₁ Co ₁ Mn ₁ O ₄₇ ,., IiA

550
525

410 390

550 435

(Continuation of Table II)

Catalyst composition Per Feed,
Mole O, N, steam Propylene
sales
Yes Selectivity,
% CO CO, Comparison
example py ever
By acrylic len NH, 2.8 6.8 8.9 corridor, acid 13.1 10.6 Ρ «noMOisFe.BiiNiii BMe ₁ COiMn ₁ O ₄₇ - 1 3.0 7.0 3.8 % nitrile 11 16 ι Po ₁ O ₈ Mo ₁₂ Fe ₀₁₈ Bi ₁ Ni ₈₁₅ O ₁₇₁₁ 1 1.2 99.5 53 2 1.2 90 51

Examples 15 and 16

According to Example 1, the catalysts mentioned in Table III are prepared and used for the preparation used by acrylonitrile. The results are shown in Table III.

Table III

at
game Catalyst composition React
functional
tempe-
ratiir,
⁰ C Space-
ge
Schwin-
age,
Hour " ¹ Loading
relationship,
Mole
CH ,: NH ,: O ₁ :
N ₁ : steam Per-
pylene
around-
sentence,
% acrylic
acid
nitrile Select
° /
HCN vity,
1
CO CO ₂ 15th
16 TI ₀₁₃ Po ₄ Mo ₁₁ SFe ₁ BiC ₆ MnJjNi ₇ O ₄₇₁₉
Tl ₀₁₆ P ₁ Mo ₁₂ Fe ₄ Bi ₁ COeO ₆₇₁₈ 431
450 600
600 1: 1.07: 2.5: 8: 4
1: 1.10: 2.3: 8: 4 99.8
94.8 86.1
85.1 4.7
6.2 3.8
3.2 4.0
4.9

Example 17

1. According to Example 1 (A), a catalyst is the

formula

TUP ₀₁ O ₈ Mo ₁₂ Fe ₁ Bi ₁ Ni ₄₁₅ Co ₄ O ₁ ,

manufactured.

Of the catalyst obtained are mm in a glass reaction tube having an inner diameter of 10 6 ml was charged and heated to 395 to 43o C ^0. A gas mixture of propylene, ammonia, oxygen, water vapor and nitrogen in a molar ratio is then applied

1.0: 1.1: 2.5: 3.0: 8.0

Of the catalyst obtained are mm in a glass reaction tube having an inner diameter of 10 6 ml was charged and heated to 410 ⁰ C. A gas mixture of propylene, ammonia, oxygen and nitrogen in a molar ratio is then added

1.0: 1.2: 2.3: 11

introduced at a space velocity of 550 hr. ^"1, wherein acrylonitrile is produced The dependence of the propylene conversion per pass and selectivity of the formation of acrylonitrile or of carbon monoxide and carbon dioxide from bismuth content y is graphically shown in F i g. 2,.

In practice, the formula leads to the calculation of the oxygen with a space velocity of 500 hours - ¹ solids content of the catalysts

with a space velocity of 5 S g

conducts, whereby acrylonitrile is formed. The dependence of the propylene conversion per pass, the selectivity of the formation of acrylonitrile, carbon monoxide and carbon dioxide or hydrogen cyanide on the thallium content χ is shown in FIG. 1 shown graphically. 2. According to Example 1 (A), a catalyst of the formula

manufactured. The second calcination temperature is but at 525 ° C.

g = 1.5a + 2.5b + 3c + \, 5d + 1.5e + f

to satisfactory results. Accordingly, the index g as a direct measure of the oxygen content in Example 17 (1.)

g = 47.7 + 1.5 χ
and in example 17 (2.)

S = 47.0+ 1.5;, -.

1 sheet of drawings

409509/427

Claims (1)

1 V 2 By-products does not only result in a loss of patent entitlement: it results in connections, it also makes them more difficult Isolation of the resulting acrylonitrile from the process for the production of acrylonitrile reaction products. by reacting propylene with ammonia 5 Another disadvantage is the low yield of and acrylonitrile containing oxygen or free oxygen per passage of the inert gases used at an elevated temperature in the gas pylene. This is probably due to the low Umphase in the presence of calcined, phosphorus, set / on propylene or, even if the conversion of the Molybdenum, iron and bismuth containing oxide propyiens is high, due to the low selectivity of the Supported catalysts and, if appropriate, water io formation of acrylonitrile. steam, characterized in that a further disadvantage is the formation of excessively oxy- one at temperatures of 350 to 480 ° C, pressures dated by-products such as carbon monoxide and Kohvon 0.7 to 5 at and a molar ratio of prole dioxide, thereby controlling the heat of the verpylene to ammonia to oxygen from driving is made difficult. The side reactions are 15 more exothermic than the main reaction, therefore 1.0: 1.0 to 2.0: 1.5 to 3.5 larger amounts of diluent required, to keep the heat development under control.